Hey Guys Im thinking of buying a zj for my Wife.The one Im thinking of buying has the np242 tcase in it.I have a zj with the 249 and a xj with 231 so I know how well they work, My question is:
does the 242 operate like a 249 and 231 combine basically? or Is it not comparable ? I want my wife to be able to have 4wd all time for bad weather days but she wants the option to use 2wd for better mpg but I want to know that this tcase will operate as well as the 249 and 231.Thanks Guys

haha true. I dont care about the mpgs really Im Just wondering if the 249 is better than the 242 for 4wd all time or they are pretty close. Same with the 4hi and 4lo in the 231 compared to the 242. In other words is the 242 the best of both worlds?

haha true. I dont care about the mpgs really Im Just wondering if the 249 is better than the 242 for 4wd all time or they are pretty close. Same with the 4hi and 4lo in the 231 compared to the 242. In other words is the 242 the best of both worlds?

Stick with the 249 if you're not considering things like front locker etc. Search around the forum there's lots of info but in your case probably not worth the swap unless there's a problem with your current case

I love my 242's. Had one in my 88 xj then swapped our bad 249 for a 242. Works flawless. 2wd on dry pavement and gravel when I want to have fun. 4 full time in snowy weather and even wet roads. It gets annoying spinning tires at stop lights and stop signs with the v8. Lol...I even use 4 full time on the trails until I get into the real poop. But mainly because I use 4lo a lot and 4 full time is just the other side of N. Lol....call me lazy. Go for it. You won't regret.

haha true. I dont care about the mpgs really Im Just wondering if the 249 is better than the 242 for 4wd all time or they are pretty close. Same with the 4hi and 4lo in the 231 compared to the 242. In other words is the 242 the best of both worlds?

The VC in your 249 will eventually fail. The 242 won't. So yes imo the 242 is the best of both worlds.

With a properly functioning viscous coupler, the 249's 4FT will outperform the 242's 4FT, no question. In good working order, the 249 is a very good full-time AWD case. If you need or want the selectable 4PT but also drive in situations where 4FT is a benefit (i.e. a multipurpose street/trail rig) the 242 is a solid compromise.

Mind you all of this leads up the fact that the 231 is the best of the 3 cases in terms of simplicity inside and has the best track record of not being picky between the 3 cases. You have a 98, so the VC in your case is different then the VC you'll see in the 93-95 249 cases which fail much quicker. But as Catsplat said, the 249 for all time 4wd will out perform the other 2 cases hands down. Not to mention it is the strongest case with the thickest chain of the 3. All have their ups and downs, so going to what depends on your needs, options and wants. As part of this, the 93-95 249 was a split 50/50 case, meaning half the power went upfront and half went out back 100% of the time. While the 96-98 249 case is about 10/90, with 10% power going to front, 90% going to rear until it senses a slip in the tires and then it adjust the power to both wheels.

I love my 249, snowy winter I just get in and go, no concerns and I have 200k on that case without a VC replacement. At the same time mine is starting to show slight signs of wear so I'm prepping for a swap so I'm prepared when that time does come.

There's a lot of negative talk around here about the 249 cases, but they are excellent cases, extremely durable and work. They just have that fatal flaw of the VC that will fail usually between 100k-250k. Parts usually run about 300 to fix it when it goes out, and many people say for less than that cost I can get a 242 or 231 and swap it in.

My .02, if my VC is still strong, and it's a DD that I have 0 desire to lock the front and want to have all time 4wd, I would not swap out the 249. Again, this is if there are no issues with the case. If/when a problem does arise, then it's a question of cost to repair vs cost to swap. But as said for all time 4wd you can't beat the 249.

Sorry for my lazy responses last night, was late and knew I had to be up at 4am haha

haha true. I dont care about the mpgs really Im Just wondering if the 249 is better than the 242 for 4wd all time or they are pretty close. Same with the 4hi and 4lo in the 231 compared to the 242. In other words is the 242 the best of both worlds?

Its not the best of both worlds. The 242 uses a sprocket differential for full time 4wd which behaves like an open differential. Very frustrating to be sitting there in the snow with one tire spinning. The 249 uses a viscous coupling for full time 4wd which behaves like a limited slip. Step on the gas and go. World of difference.

Most viscous couplings of the ZJ vintage are now worn out and need replacing. Its a $300-$400 unit.

i have a 242 that i use during the summer and every year (after the first when i used the 242 after the swap)i go through the hassle of putting the 249 back in. i do it because its so much better in snow and ice and i dont have to worry about anyone else who might drive it messing something up.

I see a lot of 98ZJ owners in here so I'll ask. My problem now is with the drive shaft. The donor 242 has an ESY and of course the 249 is a ISY. From what I've read, my original drive shaft is going to be too long. Mine is a Limited with an upcountry lift and I plan to put a BB on it or something later anyhow. I did some measuring from where the t-case bolts to the trans to the end of the main shaft and then on the bolt to the end of the main shaft of the 242. Both are 19" but I think that's just going to end up with me being snug and having no slip room. On the other hand the donor shaft I pulled looks substantially shorter. I guess I won't know until I get stuff mounted and see how it fits.

For the OP's consideration:

I just bought my 98 5.2 Limited and am looking at a VC going bad. Long story but I looked for an older ZJ rather than the WJ I was originally looking for because I could come out under budget by half and have money left over for repairs/mods. Anyways, the VC was a known issue going into it and I waffled for a while whether to replace the VC or do a 242/31 swap.

For me it was a simple issue of going to a more desirable case and doing it much cheaper than the cost of a VC (last I looked around $340 from a decent seller on EBay). I pulled a 242 from the junk yard for $115. It feels tight and I don't think I'm going to do a rebuild until I get it mounted and see that there is a problem rather than spending the money now. I know it's probably the fool's way but we'll see how it goes. In the case that you have to rebuild the 242 you pull, a rebuild kit is around $100-120. Now the drive shaft. I paid $20 for the donor drive shaft and was unlucky enough to end up with one thats got some dents in it. I couldn't find anymore ESY drive shafts from a selec trac, in fact the 242 we pulled was the only one we found in the whole yard. That being said, unless I can scrounge up another DS that will fit, I'm going to have to retube this one assuming it's the one that will fit. That's another $150 (rough estimate I have no idea what it'll cost). So consider my case when making your decision. If I come out of this WITHOUT a rebuild I'll have spent $285 if I have to retube my DS + about $20 in core charges. If I have to rebuild the 242 I'll come out spending probably $405. So as you can see it's not always the cheaper option. I really hope this drive shaft thing works out. Anyone else know of other DS's I could look for at the yard? Another $20 beats the **** out of retubing the donor or getting my original shortened.